Cancelled - A refined Brill-Noether theory over Hurwitz spaces

Series
Algebra Seminar
Time
Monday, March 23, 2020 - 3:00pm for 1 hour (actually 50 minutes)
Location
Skiles 005
Speaker
Hannah Larson – Stanford University – hlarson@stanford.eduhttp://web.stanford.edu/~hlarson/
Organizer
Yoav Len

This talk was cancelled due to the current status. The following is the original abstract for the talk. The celebrated Brill-Noether theorem says that the space of degree d maps of a general genus g curve to Pr is irreducible. However, for special curves, this need not be the case. Indeed, for general k-gonal curves (degree k covers of P1), this space of maps can have many components, of different dimensions (Coppens-Martens, Pflueger, Jensen-Ranganathan). In this talk, I will introduce a natural refinement of Brill-Noether loci for curves with a distinguished map CP1, using the splitting type of push forwards of line bundles to P1. In particular, studying this refinement determines the dimensions of all irreducible components of Brill-Noether loci of general k-gonal curves.